1. Field of the Invention
The present invention relates to a patient call system and more particularly to a dual activated pneumatic actuator system which is connectable to a nurse call system and to an auxiliary device, for example, an electronic device such as a television or a radio.
2. Description of the Prior Art
It is known in the art to use pneumatically actuated switches, rather than electrical switches, as part of nurse call systems. Such switches, disclosed for example in U.S. Pat. No. 3,823,285 to Dwyer, are particularly beneficial where combustion concerns may be present, as in oxygen rich environments, because the construction of the pneumatically actuated switch limits the possibility of arcing which is a problem associated with electrical switching.
The above U.S. Pat. No. 3,823,285 illustrates an example of a pneumatically actuated bulb device for a patient actuated nurse call system. This device includes a deformable pneumatic bulb to provide a source of pressurized air to operate an electrical switching circuit that is well suited for use in environments where it is undesirable to use a conventional electrical switch as discussed in the preceding paragraph.
A patient actuated call system is not only commonly used in hospital rooms but also in other health care facilities where there is a need or desire to summon personnel for help, particularly, when a patient is in a weakened or disabled condition. Most hospitals and health care institutions have signaling systems by which in each patient area, a patient may initiate a signal that is received at a station or at an allocated substation within a larger area to summon assistance. Typically, for example in a hospital, a select group of patient areas is serviced by a given nurse station where calls for assistance by patients are taken. Most patient areas must accommodate the use of oxygen even if it is only on an emergency basis whereby electrical switches commonly used in other industries cannot be utilized. The pneumatically operated switch disclosed in the aforesaid U.S. Pat. No. 3,823,285 provides an entirely satisfactory solution to the need for a pneumatically activated switching device which can operate in a very reliable fashion in hostile environments particularly atmospheres containing a high concentration of oxygen that could otherwise cause combustion. In this invention, a deformable bulb operated by the patient supplies pneumatic pressure to the substation for assistance.
A further development of a pressurizing device is disclosed in U.S. Pat. No. 5,155,309 which embodies a pneumatic bulb having an annular ring configuration with a convexly shaped actuator dome resembling a doughnut appearance to provide a distinctive identification to the bulb for distinction from other pneumatic bulbs that may be utilized for different purposes in a patient area. The construction of the pneumatic bulb includes a base plate to provide a board area of support for the bulb and support for a peripheral rim and a center post of the doughnut shaped actuator dome. The base plate includes protruding truncated conical members relied upon to maintain the doughnut shaped actuator at a fixed or pre-established location on a patient's mattress so that the patient can reliably find the bulb to summon help.
Examples of other known nurse call systems can be found in U.S. Pat. Nos. 4,702,443; 4,484,367; 4,298,863; and 3,781,843. In U.S. Pat. No. 4,702,443, a cord holding device is disclosed wherein a holding member supports a cord to allow limited movement of the cord, the end of which carries a push button electric switch. In U.S. Pat. No. 4,484,367, a side rail of a patient's bed is wrapped with a flexible sheet having a pocket for receiving an electronic push button device serving as a call device for summoning a nurse. U.S. Pat. No. 4,298,863 discloses a patient call system in which a patient operated transducer, mounted on a patient's face or a portion of the body, is interconnected by pneumatic tubing to a pneumatically actuated switch that is part of an electronic monitoring system. U.S. Pat. No. 3,781,843 discloses a bed guard system having restraining rails fitted with a detector. Each detector is formed with an elongated rail engaging pocket shape to fit on the rail surface and an overlying elongated internal cavity extending generally the length of the rail. The internal cavity forms a site for a fluid material which can be pressurized by an applied pressure to the top surface of the rail covering.
The above known pneumatically actuated patient call systems generally have a single switch for delivering pressurized air for triggering a switching device to produce an electrical signal in a nurse station for assistance.
There is a need to provide a pneumatically actuator for a patient call system which includes at least two actuators, one for delivering pressurized air for triggering a device to produce an electrical signal in a nurse station for assistance and the other for delivering pressurized air for triggering a device to produce an electrical signal to operate an auxiliary device, for example an electronic device such as a television or a radio.
There is a further need to provide an improved pneumatic actuator system including a pneumatic actuator for triggering at least two electrical devices, one connectable to the nurse station for assistance and the other connectable to an auxiliary device, for example an electronic device such as a television or a radio.